Sixty-Seven Years of Land-Use Change in Southern Costa Rica.
Sixty-Seven Years of Land-Use Change in Southern Costa Rica.
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DOI：
10.1371/journal.pone.0143554
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Kormann U
中科院分区：
文献类型：
--
作者：
Zahawi RA;Duran G;Kormann U
生境丧失和森林破碎化是对热带景观生物多样性和相关生态系统服务的最大威胁。我们使用附近的哥斯达黎加南部的拉斯克鲁塞斯生物站作为一个区域性的案例研究，记录七十年的土地利用变化在新热带地区研究最深入的网站之一。虽然1947年前的潮湿森林基本上完好无损，但1952年的移民潮在短时间内引发了迅速的变化。在分析的每个时间间隔内，（1947-1960，1960-1980，1980-1997，1997-2014），尽管绝大多数森林损失（>90%）发生在前两个时间间隔内（1947-1960年，1960-1980年），年森林砍伐率分别为2.14%和3.86%。此后，这一比率下降到<2%，最近休耕地区的森林恢复抵消了这一比率，但总体森林覆盖率继续下降。目前，研究区约有27.9%的面积被森林覆盖。与此同时，随着每次连续的调查，该区域从单一的毗连森林转变为一系列逐渐变小的森林碎片。由于许多森林碎片形状不规则，核心生境数量的大幅减少被边缘生境比例的增加所掩盖。然而，结构连通性仍然很高，在监测站3公里半径范围内有一个由>100公里的线状植被带组成的广阔网络，这可能有助于某些物种的群落级移动。尽管森林丧失的程度很大，但过去二十年来进行的大量区域森林一级的研究表明，鸟类和哺乳动物等许多生物群体仍然存在。尽管如此，数量和质量的持续下降的剩余栖息地（约30%的剩余森林是次要的），以及灭绝债务的威胁（或物种损失的时间滞后），可能会导致更多的物种灭绝，如果不采取更积极的保护措施来扭转目前的趋势，反映了世界上许多其他热带地区的模式。
Habitat loss and fragmentation of forests are among the biggest threats to biodiversity and associated ecosystem services in tropical landscapes. We use the vicinity of the Las Cruces Biological Station in southern Costa Rica as a regional case study to document seven decades of land-use change in one of the most intensively studied sites in the Neotropics. Though the premontane wet forest was largely intact in 1947, a wave of immigration in 1952 initiated rapid changes over a short period. Overall forest cover was reduced during each time interval analyzed (1947–1960, 1960–1980, 1980–1997, 1997–2014), although the vast majority of forest loss (>90%) occurred during the first two time intervals (1947–1960, 1960–1980) with an annual deforestation rate of 2.14% and 3.86%, respectively. The rate dropped to <2% thereafter and has been offset by forest recovery in fallow areas more recently, but overall forest cover has continued to decline. Approximately 27.9% of the study area is forested currently. Concomitantly, the region shifted from a single contiguous forest to a series of progressively smaller forest fragments with each successive survey. A strong reduction in the amount of core habitat was paralleled by an increased proportion of edge habitat, due to the irregular shape of many forest fragments. Structural connectivity, however, remains high, with an expansive network of >100 km of linear strips of vegetation within a 3 km radius of the station, which may facilitate landscape-level movement for some species. Despite the extent of forest loss, a substantial number of regional landscape-level studies over the past two decades have demonstrated the persistence of many groups of organisms such as birds and mammals. Nonetheless, the continued decline in the quantity and quality of remaining habitat (~30% of remaining forest is secondary), as well as the threat of an extinction debt (or time lag in species loss), may result in the extirpation of additional species if more proactive conservation measures are not taken to reverse current trends–a pattern that reflects many other tropical regions the world over.